AERMOD View

AERMOD View - Reading AERMOD SFC File Headers

AERMET, the meteorological preprocessor used to generate meteorological data for use in the AERMOD air dispersion model, creates two unique files:

• A surface file (*.SFC) containing surface-level variables and turbulence scaling parameters calculated by AERMET, and
• A profile file (*.PFL) containing multi-level variables for boundary layer profile analysis in AERMOD.

AERMOD View - Modeling NO2 in AERMOD – ARM2

One of the biggest changes to the AERMOD modeling system in the 18081 model update was the removal of the original Ambient Ratio Method (ARM) for analyzing conversion of NO_x to NO₂. This option, based on Chu & Meyer’s 1991 work presented at that year’s Air & Waste Management Association’s annual conference, used a single ratio to convert all NO_x concentrations to NO₂. The national default value was 75% for annual averages, and subsequent guidance recommended a value of 80% for the hourly standard.

AERMOD View - Choosing Pollutants

As the preferred air dispersion model for analysis of air pollutant concentrations in the ambient environment up to 50-km, AERMOD is used for a wide variety of buoyant and neutrally-buoyant releases. One recurring question about AERMOD is what pollutants it can (or cannot) model. Coded into the model is a list of pollutant types used to identify the pollutant being modeled for a particular run.